Acaricidal pyridinium salts

ABSTRACT

Compounds of formula   &lt;IMAGE&gt;   in which R1, R2, R3, R4 and R5 are the same or different and each represents hydrogen, halogen, nitro, alkyl, substituted alkyl, alkoxy, carboxy or an ester, amide or mono- or di-substituted amide thereof, aryl, heterocyclic, aralkyl, cyano or hydroxy, with the proviso that R3 does not represent a second group of formula I or II in which R3 is merely a bond; R6 represents a group of formula COR8, COOR8, CONR8R9 or SO2R8, in which R8 represents alkyl, substituted alkyl, aryl, substituted aryl, aralkyl, substituted aralkyl, aralkenyl, substituted aralkenyl, cycloalkyl or heterocyclic, and R9 represents hydrogen, alkyl, substituted alkyl, phenyl or substituted phenyl; R7 represents hydrogen, alkyl of 1 to 4 carbon atoms or a group as defined under R6; and X-represents one equivalent of an anion are acaricides, especially for use on crops.

This is a divisional application of application Ser. No. 545,700, filedJan. 30, 1975, now U.S. Pat. No. 4,025,632, which in turn is adivisional application of application Ser. No. 321,476, filed Jan. 5,1973, now U.S. Pat. No. 3,886,171.

This invention relates to acaricides.

A new group of acaricides has been discovered, which has very valuableproperties. The compounds are of low mammalian toxicity. Moreover theyare of low herbicidal and insecticidal activity and hence can be used tocombat acarids on desired plants without harming the plants and tocombat acarids without harming beneficial insects such as bees.Furthermore, besides having direct contact action against acarids, manyof the compounds are systemic within plants and hence can be used onplants even though not all the affected parts of the plant are contactedduring application and even by application to the soil in which theplants are growing or are to grow.

Accordingly, the invention includes a method of combating acarids at alocus infested or liqble to be infested with them, which methodcomprises applying to the locus an acarid-combating amount of a compoundof general formula ##STR2## in which R¹, R², R³, R⁴ and R⁵ are the sameor different and each represents hydrogen, halogen (for example chloroor bromo), nitro, alkyl (for example of 1 to 4 carbon atoms such asmethyl, ethyl or isopropyl), substituted alkyl (for example the alkylgroup substituted by hydroxy or halogen, such as hydroxymethyl,chloromethyl or trifluoromethyl), alkoxy (for example of 1 to 4 carbonatoms such as methoxy, ethoxy or isopropoxy), carboxy or an ester (forexample with an alkanol of 1 to 4 carbon atoms), amide or mono- ordi-substituted amide (for example substituted by alkyl of 1 to 4 carbonatoms) thereof, aryl (for example phenyl), heterocyclic (for examplefuryl, morpholino or a second group of formula I or II in which one ofR¹, R², R³, R⁴ and R⁵ is merely a bond), aralkyl (for example whosealkyl group contains 1 to 4 carbon atoms, such as benzyl or phenethyl),cyano or hydroxy; R⁶ represents a group of formula COR⁸, CO.OR⁸, CONR⁸R⁹ or SO₂ R⁸ in which R⁸ represents alkyl (for example of 1 to 8preferably 1 to 4 carbon atoms such as methyl, ethyl or isopropyl),substituted alkyl (for example the alkyl group substituted by halogen,alkoxycarbonyl of 2 to 5 carbon atoms, alkoxy, e.g. of 1 to 4 carbonatoms, or by phenoxy substituted by halogen and/or alkyl of 1 to 4carbon atoms, such as trifluoromethyl, chloroethyl, ethoxyethyl or2-methyl-4-chlorophenoxymethyl), aryl (for example phenyl), substitutedaryl (for example the aryl group substituted by one or more groupsselected from halogen, alkyl of 1 to 4 carbon atoms, acetamido, nitroand alkoxy of 1 to 4 carbon atoms, such as chlorophenyl, dichlorophenyl,tolyl, xylyl, fluorophenyl, nitrophenyl, methoxyphenyl or3-methyl-4-chlorophenyl), aralkyl (for example whose alkyl groupcontains 1 to 4 carbon atoms, such as benzyl), substituted aralkyl (forexample the aralkyl group substituted by halogen, such as chlorobenzyl),aralkenyl (for example styryl), substituted aralkenyl (for example thearalkenyl group substituted by halogen, such as chlorostyryl),cycloalkyl (for example of 3 to 8 carbon atoms, such as cyclohexyl) orheterocyclic (for example furyl, thienyl, benzofuryl or pyridyl), and R⁹represents hydrogen, alkyl (for example of 1 to 8 preferably 1 to 4carbon atoms such as methyl, ethyl or isopropyl), substituted alkyl (forexample the alkyl group substituted by halogen or alkoxy, e.g. of 1 to 4carbon atoms, such as trifluoromethyl, chloroethyl or ethoxyethyl),phenyl or substituted phenyl (for example substituted by halogen oralkyl of 1 to 4 carbon atoms, such as chlorophenyl, dichlorophenyl,tolyl or xylyl); R⁷ represents hydrogen, alkyl of 1 to 4 carbon atoms ora group as defined uner R⁶ ; and X⁻ represents one equivalent of ananion (for example (l⁻, Br⁻, I⁻, CH₃ SO₄ -- , NO₃ -- or 1/2 SO₄ ²⁻);with the priviso that R³ is not a second group of formula I or II inwhich R³ is merely a bond. The substituents defined above include acidicand basic groups and where salt formation can take place as a result atsuch groups, the compounds may be present as such salts. For example,1-nicotinamido-3-methylpyridinium chloride may be in the form of itshydrochloride, 1-nicotinamido-3-methylpyridinium chloride hydrochloride.

In addition, the invention includes as new compounds the presentcompounds except those in which R⁶ represents acetyl, propionyl,trifluoroacetyl, benzoyl, methoxycarbonyl, ethoxycarbonyl,p-tolylsulphonyl, sulphanilyl or N-acetylsulphanilyl.

The invention also provides acaricidal compositions containing thepresent compounds, particularly a composition comprising such a compoundtogether with a surface active agent; a solid composition comprisingsuch a compound together with a solid carrier; a liquid compositioncomprising such a compound together with a hydrocarbon of boiling pointin the range 130°-270° C; and a composition comprising such a compoundtogether with another agrochemical pesticide especially anotheracaricide.

The compounds of formula I may be prepared by reacting a1-amino-pyridinium salt of formula ##STR3## with a halide or anhydrideof formula R⁶ Y or R⁶ OR⁶ respectively (in which Y represents halogen).The reaction may be carried out in an organic solvent in which thedesired product is insoluble, for example a hydrocarbon such as xylene.Alternatively the reacton may be carried out without a solvent, usingexcess of the compound R⁶ Y or R⁶ OR⁶.

Alternatively, compounds of formula I may be prepared by reacting acompound of formula II with a compound of formula R⁷ X. When R⁷represents hydrogen, an external salt of formula I corresponding to theinternal salt of formula II is simply prepared; but when R⁷ representsother than hydrogen (e.g. when the compound of formula R⁷ X is dimethylsulphate or p-chlorobenzoyl chloride), an external salt of formula Iwhich has no counterpart of formula II is prepared.

The compounds of formula II may be prepared by treating those of formulaI wherein R⁷ represents hydrogen with a base, such as sodium hydroxide.

It can be seen that the compounds of formula II are the correspondinginternal salts of the compounds of formula I wherein R⁷ representshydrogen. Such compounds of the two types are equivalent. In aqueoussolution of such compounds of formula I an equilibrium exists with thecompounds of formula II, for example: ##STR4## Such pairs of equivalentcompounds are of similar activity in use. Since in the compounds offormula I it is the cation which is responsible for the acaricidalactivity, any anion can generally be employed and it can thus be chosenbearing other factors in mind such as convenience in manufacture of thecation. X⁻ is suitably chloride.

In a particular embodiment of the present compounds R¹, R², R³, R⁴ andR⁵ are the same or different and each represents hydrogen, halogen,nitro, alkyl, substituted alkyl, alkoxy, carboxy or an ester, amide ormono- or di-substituted amide thereof, aryl, aralkyl, cyano or hydroxy.New compounds within this group include the compounds in which R⁶represents CONR⁸ R⁹ ; COR¹⁰ in which R¹⁰ represents substituted aryl,aralkyl, substituted aralkyl, aralkenyl, substituted aralkenyl,cycloalkyl or heterocyclic; COOR¹¹ in which R¹¹ represents substitutedalkyl, aryl, substituted aryl, aralkyl, substituted aralkyl, aralkenyl,substituted aralkenyl, cycloalkyl or heterocyclic; or SO₂ R¹² in whichR¹² represents alkyl, substituted alkyl, aryl, aralkyl, substitutedaralkyl, aralkenyl, substituted aralkenyl, cycloalkyl or heterocyclic.

In another particular embodiment, R¹, R², R³, R⁴ and R⁵ are the same ordifferent and each represents hydrogen, halogen, nitro, alkyl, alkoxy,carboxy or an ester, amide or mono- or di-substituted amide thereof,aryl, aralkyl or hydroxy;

R⁸ represents alkyl, substituted alkyl, phenyl or substituted phenyl;and

R⁷ represents hydrogen. Preferred amongst this group of compounds arethose wherein R⁸ is phenyl optionally substituted, preferablymonosubstituted, by chlorine. New compounds within the group include thecompounds in which R⁶ represents CONR⁸ R⁹ ; COR¹⁰ in which R¹⁰represents substituted phenyl; COOR¹¹ in which R¹¹ representssubstituted alkyl, phenyl or substituted phenyl; or SO₂ R¹² in which R¹²represents alkyl, substituted alkyl or phenyl.

A more specific group of the present compounds are those wherein R¹, R²,R³, R⁴ and R⁵ are the same or different and each represents hydrogen,halogen, nitro, alkyl of 1 to 4 carbon atoms, alkyl of 1 to 4 carbonatoms substituted by hydroxy or halogen, alkoxy of 1 to 4 carbon atoms,carboxy, alkoxycarbonyl whose alkoxy group contains 1 to 4 carbon atoms,carbamoyl, N-alkylcarbamoyl whose alkyl group contains 1 to 4 carbonatoms, N,N-dialkylcarbamoyl whose alkyl groups are the same or differentand contain 1 to 4 carbon atoms, phenyl, furyl, morpholino, a secondgroup of formula I or II in which one of R¹, R², R³, R⁴ and R⁵ is merelya bond, phenylalkyl of 7 to 10 carbon atoms, cyano or hydroxy, with theproviso that R³ does not represent a second group of formula I or II inwhich R³ is merely a bond;

R⁸ represents alkyl of 1 to 8 carbon atoms; alkyl of 1 to 8 carbon atomssubstituted by halogen, alkoxycarbonyl of 2 to 5 carbon atoms, alkoxy of1 to 4 carbon atoms, or by phenoxy substituted by halogen and/or alkylof 1 to 4 carbon atoms; phenyl; naphthyl; phenyl or naphthyl substitutedby one or more groups selected from halogen, alkyl of 1 to 4 carbonatoms, nitro and alkoxy of 1 to 4 carbon atoms; phenylalkyl of 7 to 10carbon atoms substituted by halogen; styryl; styryl substituted byhalogen; cycloalkyl of 3 to 8 carbon atoms; furyl; thienyl; benzofuryl;or pyridyl; and R⁹ represents hydrogen; alkyl of 1 to 8 carbon atoms;alkyl of 1 to 8 carbon atoms substituted by halogen or alkoxy of 1 to 4carbon atoms; phenyl; or phenyl substituted by halogen or alkyl of 1 to4 carbon atoms.

For convenience in manufacture, the present compounds can be thosewherein R¹, R², R³, R⁴ and R⁵ are the same or different and eachrepresents hydrogen or alkyl of 1 to 4 carbon atoms;

R⁸ represents alkyl of 1 to 8 carbon atoms; alkyl of 1 to 8 carbon atomssubstituted by alkoxycarbonyl of 2 to 5 carbon atoms or by phenoxysubstituted by halogen and/or alkyl of 1 to 4 carbon atoms; phenyl;naphthyl; phenyl substituted by one or more groups selected fromhalogen, alkyl of 1 to 4 carbon atoms nitro and alkoxy of 1 to 4 carbonatoms; phenylalkyl of 7 to 10 carbon atoms; phenylalkyl of 7 to 10carbon atoms substituted by halogen; styryl; styryl substituted byhalogen; cycloalkyl of 3 to 8 carbon atoms; furyl; thienyl; benzofuryl;or pyridyl;

R⁹ represents hydrogen or alkyl of 1 to 8 carbon atoms; and

R⁷ represents hydrogen, alkyl of 1 to 4 carbon atoms or benzoylsubstituted by halogen. A preferred group of these compounds are thesewherein R⁸ represents alkyl of 1 to 8 carbon atoms; alkyl of 1 to 8carbon atoms substituted by phenoxy substituted by halogen; phenyl;phenyl substituted by one or more groups selected from halogen, alkyl of1 to 4 carbon atoms, nitro and alkoxy of 1 to 4 carbon atoms;phenylalkyl of 7 to 10 carbon atoms; styryl; styryl substituted byhalogen; cycloalkyl of 3 to 8 carbon atoms; benzofuryl; or pyridyl.

It is preferred that R⁷ represents hydrogen.

Usually at least three, and preferably at least four, of R¹, R² R³, R⁴and R⁵ represent hydrogen.

Preferably at least one of R¹ and R⁵ represents hydrogen.

The most preferred compounds are those wherein R⁶ represents COR⁸ orCOOR⁸ especially where R⁸ represents phenyl substituted by one or moregroups selected from halogen, alkyl of 1 to 4 carbon atoms, nitro andalkoxy of 1 to 4 carbon atoms. Such especially preferred compounds arenot only highly active but are active over long periods, e.g.1-(p-chlorobenzamido)pyridinium chloride can protect cucumbers for 2months or more. Moreover, such especially preferred compounds are activeagainst strains of mites which are resistant to standard acaricides,such as Dicofol, Chlorobenzilate, Tetradifon and Dimethoate.

A preferred group of new compounds are those of general formula I or IIin which R¹, R², R³, R⁴ and R⁵ are the same or different and eachrepresents hydrogen or alkyl of 1 to 4 carbon atoms;

R⁶ represents a group of formula COR¹⁰, COOR¹¹, or CONR¹³ R¹⁴ in whichR¹⁰ represents phenyl substituted by one or more groups selected fromhalogen, alkyl of 1 to 4 carbon atoms, nitro and alkoxy of 1 to 4 carbonatoms; phenylalkyl of 7 to 10 carbon atoms; phenylalkyl of 7 to 10carbon atoms substituted by halogen; styryl; styryl substituted byhalogen; cycloalkyl of 3 to 8 carbon atoms; furyl; pyridyl; benzofurylor thienyl; R¹¹ represents phenyl; phenyl substituted by halogen and/oralkyl of 1 to 4 carbon atoms; or benzofuryl; R¹³ represents alkyl of 1to 8 carbon atoms; phenyl; phenyl substituted by one or more groupsselected from halogen, alkyl of 1 to 4 carbon atoms and alkoxy of 1 to 4carbon atoms; and R¹⁴ represents hydrogen or alkyl of 1 to 8 carbonatoms;

R⁷ represents hydrogen, alkyl of 1 to 4 carbon atoms or benzoylsubstituted by halogen; and

X⁻ represents one equivalent of an anion. Desirably within this groupR¹⁰ represents phenyl substituted by one or more groups selected fromhalogen, alkyl of 1 to 4 carbon atoms, nitro and alkoxy of 1 to 4 carbonatoms; phenylalkyl of 7 to 10 carbon atoms; styryl; styryl substitutedby halogen; cycloalkyl of 3 to 8 carbon atoms; or pyridyl; R¹¹represents phenyl; phenyl substituted by halogen and/or alkyl of 1 to 4carbon atoms; or benzofuryl; and R¹³ represents alkyl of 1 to 8 carbonatoms or phenyl substituted by halogen.

Outstandingly active and most preferred are compounds of general formulaI and II in which four of R¹, R², R³, R⁴ and R⁵ represent hydrogen andthe fifth represents hydrogen or alkyl of 1 to 4 carbon atoms; R⁶represents benzoyl substituted by one or two substituents selected fromhalogen, alkyl of 1 to 4 carbon atoms and nitro; and X⁻ represents oneequivalent of an anion. The most promising particular compounds withinthis group are:

1-(p-chlorobenzamido)pyridinium salts;

1-(p-chlorobenzamido)-2-methylpyridinium salts;

1-(p-chlorobenzamido)-3-methylpyridinium salts;

1-(p-chlorobenzamido)-4-methylpyridinium salts;

1-(3,4-dichlorobenzamido)pyridinium salts; and

1-(4-nitrobenzamido)pyridinium salts; especially the first-mentioned andespecially the internal salts of these compounds and the chlorides ofthe first five.

The present compounds are usually employed in the form of compositionscontaining the active ingredients. Usually compositions are initiallyproduced in the form of concentrates, e.g. containing 20-98% activeingredient, and these are diluted with water for application, e.g. sothat the concentration of active ingredient is 0.01-0.5%. Parts andpercentages in this specification are by weight unless otherwiseindicated.

The compositions normally contain a carrier and/or a surface activeagent.

The carrier may be a liquid, e.g. water (e.g. water used to dilute aconcentrate for application). Many of the compounds are water solublecrystalline solids and can be used in the form of aqueous solutions. Ifwater is employed as carrier in a concentrate, an organic solvent mayalso be present as carrier, though this is not usually employed. Asurface active agent may advantageously be present.

The carrier may be a liquid other than water, for example an organicsolvent, usually a water-immiscible solvent, e.g. a hydrocarbon whichboils within the range 130°-270° C, in which the compounds are dissolvedor suspended. A concentrate containing an organic solvent suitably alsocontains a surface active agent so that the concentrate acts as aself-emulsifiable oil on admixture with water.

The carrier may be a solid, which may be finely divided. Examples ofsuitable solids are clays, sand, mica, chalk, attapulgite, diatomite,perlite and sepiolite, and synthetic solid carriers, e.g. silicas,silicates and lignosulphonates.

Wettable powders soluble or dispersible in water may be formed byadmixing the compounds with or without a carrier with a surface activeagent.

Aqueous solutions and wettable powders are the preferred concentratessince the compounds are of comparatively low solubility in organicsolvents such as hydrocarbons. A compound of formula I where R⁷represents hydrogen tends to be more soluble in water but less solublein organic solvents such as hydrocarbons than the corresponding compoundof formula II. Thus, in making up an emulsifiable concentrate in ahydrocarbon the compound in the form of an internal salt of formula IIwould generally be favoured, while in making up an aqueous solution thecompound in the form of an external salt of formula I would generally befavoured.

The term `surface active agent` is used in the broad sense to includematerials variously called emulsifying agents, dispersing agents andwetting agents. Such agents are well known in the art.

The surface active agents used may comprise anionic surface activeagents, for example soaps, fatty sulphate esters such as dodecyl sodiumsulphate, octadecyl sodium sulphate and cetyl sodium sulphate, fattyaromatic sulphonates such as alkyl-benzene sulphonates orbutyl-naphthalene sulphonates, more complex fatty sulphonates such asthe amide condensation product of oleic acid and N-methyl taurine or thesodium sulphonate of dioctyl succinate.

The surface active agents may also comprise non-ionic agents, forexample condensation products of fatty acids, fatty alcohols or fattysubstituted phenols with ethylene oxide, or fatty esters and ethers ofsugars or polyhydric alcohols, or the products obtained from the latterby condensation with ethylene oxide, or the products known as blockcopolymers of ethylene oxide and propylene oxide.

The surface active agents may also comprise cationic agents, for examplecetyl trimethylammonium bromide.

Preferred surface active agents are non-ionic surface active agents.

The present compounds are useful as acaricides. They are particularlyactive against the eggs of mites, preventing the eggs from hatching, andare also active against the larval and nymphal stages. Furthermore, whenadult female mites are treated with a non-toxic dosage of the compounds,the mites' eggs fail to hatch.

The present active compounds may be admixed with other agrochemicalpesticides, for example herbicides, insecticides, fungicides or otheracaricides, or fertilizers. Examples of pesticides with which thecompounds may be mixed are Dicofol(2,2,2-trichloro-1,1-di(4-chlorophenyl)ethanol), Fenazaflor(5,6-dichloro-1-phenoxycarbonyl-2-trifluoromethylbenzimidazole),tricyclohexyltin hydroxide, Tetradifon (2,4,4',5-tetrachlorodiphenylsulphone), Formetanate (3-dimethylaminomethyleneiminophenylN-methylcarbamate), Chlorodimeform(N,N-dimethyl-N'-(2-methyl-4-chlorophenyl)formamidine), Chlorobenzilate(ethyl 4,4'-dichlorobenzilate), Quinomethionate(6-methyl-2-oxo-1,3-dithiolo[4,5-b]quinoxaline), Endosulfan(6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepin3-oxide), Chlorodecone(decachlorooctahydro-1,3,4-metheno-2H,5H,cyclobuta[cd]pentalen-2-one),bis(pentachloro-2,4-cyclopentadien-1-yl), Chloropropylate (isopropyl4,4'-dichlorobenzilate), Bromopropylate (isopropyl4,4'-dibromobenzilate), Thioquinox(2-thio-1,3-dithiolo-[4,5-b]quinoxaline), Dinocap (dinitrooctylphenylcrotonate), Binapacryl (2-sec-butyl-4,6-dinitrophenyl2-methylcrotonate), Dinobuton (2-sec-butyl-4,6-dinitrophenyl isopropylcarbonate), Naled (1,2-dibromo-2,2-dichloroethyl dimethyl phosphate),Monocrotophos (dimethyl 1-methyl-2-(methylcarbamoyl)-vinyl phosphate)Demeton (diethyl 2-(ethylthio) ethylthiophosphate), Phorate (O,O-diethylS-(ethylthiomethyl) phosphorodithioate), Oxydemeton-methyl (O,O-dimethylS-(2,ethylsulphinylethyl)phosphorothioate), Ethion (tetraethylS,S'-methylenebis(phosphorodithioate)), Formothion(S-(N-formyl-N-methylcarbamoylmethyl) dimethyl phosphorodithioate),Ethoate-methyl (S-(N-ethylcarbamoylmethyl) dimethyl phosphorodithioate),Dimethoate (dimethyl S-(N-methylcarbanoylmethyl) phosphorodithioate),Cyanthoate (S-(N-(1-cyano-1-methylethyl)carbamoylmethyl) diethylphosphorothioate), EPN (O-ethyl O-p-nitrophenyl phenylphosphonothioate),Carbophenothion (S-(4-chlorophenylthiomethyl) diethylphosphorodithioate), Methidathion(S-(2,3-dihydro-5-methoxy-2-oxo-1,3,4-thiadiazol-3-ylmethyl) dimethylphosphorodithioate), Chloropyrifos (diethyl 3,5,6-trichloro-2-pyridylphosphorothionate), Diazinon (diethyl 2-isopropyl-6-methyl-4-pyrimidinylphosphorothionate), azinphos-ethyl (diethylS-(4-oxo-1,2,3-benzotriazin-3-ylmethyl) phosphorodithioate),Azinphos-methyl (dimethyl S-(4oxo-1,2,3-benzotriazin-3-ylmethylphosphorodithioate), Fenson (4-chlorophenyl benzenesulphonate), Tetrasul(2,4,4',5-tetrachlorodiphenyl sulphide), Chlorbenside (4-chlorobenzyl4-chlorophenyl sulphide), Chlorfensulphide (4-chlorophenyl2,4,5-trichlorophenylazo sulphide) 2-(p-tert-butylphenoxy)-1-methylethyl2-chloroethyl sulphite, 2-(p-tert-butylphenoxy)cyclohexyl 2-propynylsulphite, Aldicarb (2-methyl-2-(methylthio)propionaldehydeO-(methylcarbamoyl)oxime), Methomyl (S-methyl-N-(methylcarbamoyloxy)thioacetimidate), Methiocarb (4-methylthio-3,5-xylyl N-methylcarbamate),and Benomyl (methyl 1-(butylcarbamoyl)benzimidazole-2-carbamate).

Particularly useful are mixtures with other acaricides which have rapidknockdown to adult mites. These mixtures combine activity against adultmites and ovicidal activity against the following generation. Aparticularly suitable such acaricide is Dicofol.

Mixtures with insecticides are useful in broadening the spectrum of pestspecies against which the compositions are effective.

Mixtures with fungicides can combine protection against mites withprotection against fungi. Particularly useful are mixtures withfungicides controlling scab and mildew diseases, such as Benomyl,Dinocap and Quinomethionate.

The present invention may be formed by admixing the ingredients.

The compounds may be applied to stored products, animals, the land, thesoil or plants. The compounds are of interest particularly to combatmites which infest or are liable to infest desired plants especiallycrops and particularly food crops. Preferably, the compounds are appliedto crops or to soil in which crops are growing or are immediately afterapplication to grow. The compounds are safe to a wide variety of cropsand can be used against mites in the field or in the greenhouse.Examples of crops on which the compounds can be used are apples, pears,strawberries, plums, citrus, vines, cotton, ornamentals, cucumbers andtomatoes. When applied to land, the soil or plants, the compounds maygenerally be used at a rate within the range 0.1-4, preferably 0.1-2, kgper hectare. They are active against various mite species for examplethe greenhouse red spider mite, Tetranychus telarius and hop red spidermite Tetranchus urticae.

The invention is illustrated by the following Examples.

EXAMPLE 1

1-Aminopyridinium chloride (104 parts) and p-chlorobenzoyl chloride (150parts) were heated in xylene (750 parts) at 140° C for 4 hours. Thesolid product was filtered off and recrystallised from n-butanol to give1-(p-chlorobenzamido)pyridinium chloride (209 parts, 97% yield), meltingpoint 241° C.

Analysis: Found: C, 53.60; H, 3.85; N, 10.60%; C₁₂ H₁₀ Cl₂ N₂ Orequires: C, 53.55; H, 3.75; N, 10.41%.

EXAMPLE 2

1-Aminopyridinium chloride (20 parts) and n-butyric anhydride (100parts) were heated at 100° C for 4 hours. On cooling, a crystallinesolid formed which was filtered off and washed with ethyl acetate togive 1-butyramidopyridinium chloride (19 parts, 62% yield), meltingpoint 125° C.

Analysis: Found: C, 53.70; H, 6.30; N, 14.15%; C₉ H₁₃ ClN₂ O requires:C, 53.87; H, 6.53; N, 13.96%.

EXAMPLES 3-95

The following were prepared by analogous methods to those of Examples 1and 2:

    __________________________________________________________________________    1-Acetamidopyridinium chloride          m.p.                                                                             222° C                      1-(Ethoxycarbonylamino)pyridinium chloride                                                                            m.p.                                                                             160° C                      1-Nonanamidopyridinium chloride         m.p.                                                                             139° C                      1-Benzamidopyridinium chloride          m.p.                                                                             233° C                      1-(p-Fluorobenzamido)pyridinium chloride                                                                              m.p.                                                                             230° C                      1-(p-Toluamido)pyridinium chloride      m.p.                                                                             245° C                      1-(2,4-Dichlorobenzamido)pyridinium chloride                                                                          m.p.                                                                             242° C                      1-(p-Nitrobenzamido)pyridinium chloride m.p.                                                                             240° C                      1-(m-Nitrobenzamido)pyridinium chloride m.p.                                                                             200° C                      1-(p-Chlorobenzamido)-2-methylpyridinium chloride                                                                     m.p.                                                                             195° C                      1-(p-toluamido)-2-methylpyridinium chloride                                                                           m.p.                                                                             248° C                      1-(3,4-dichlorobenzamido)pyridinium chloride                                                                          m.p.                                                                             218° C                      1-benzamido-2-methylpyridinium chloride m.p.                                                                             208° C                      1-(3,4-dichlorobenzamido)-2-methylpyridinium chloride                                                                 m.p.                                                                             220° C                      1-(o-chlorobenzamido)pyridinium chloride                                                                              m.p.                                                                             203° C                      1-(p-anisamido)pyridinium chloride      m.p.                                                                             219° C                      1-(p-nitrobenzamido)-2-methylpyridinium chloride                                                                      m.p.                                                                             200° C                      1-(o-iodobenzamido)pyridinium chloride  m.p.                                                                             230° C                      1-(p-chlorobenzamido)-4-methylpyridinium chloride                                                                     m.p.                                                                             248° C                      1-(o-toluamido)pyridinium chloride      m.p.                                                                             203° C                      1-(o-toluamido)-4-methylpyridinium chloride                                                                           m.p.                                                                             205-8° C                    1-(p-tert-butylbenzamido)pyridinium chloride                                                                          m.p.                                                                             234-6° C                    1-(p-tert-butylbenzamido)-4-methylpyridinium chloride                                                                 m.p.                                                                             222-5° C                    1-(o-chlorobenzamido)-2-methylpyridinium chloride                                                                     m.p.                                                                             220° C                      1-(m-chlorobenzamido)pyridinium chloride                                                                              m.p.                                                                             230° C                      1-(m-chlorobenzamido)-2-methylpyridinium chloride                                                                     m.p.                                                                             203° C                      1-(m-chlorobenzamido)-3-methylpyridinium chloride                                                                     m.p.                                                                             195° C                      1-(m-chlorobenzamido)-4-methylpyridinium chloride                                                                     m.p.                                                                             228° C                      1-(p-chlorobenzamido)-3-methylpyridinium chloride                                                                     m.p.                                                                             214-6° C                    1-(p-chlorobenzamido)-2-ethylpyridinium chloride                                                                      m.p.                                                                             191-3° C                    1-(p-chlorobenzamido)-2,4-dimethylpyridinium chloride                                                                 m.p.                                                                             224° C                      1-(p-chlorobenzamido)-3,5-dimethylpyridinium chloride                                                                 m.p.                                                                             222-6° C                    1-(p-chlorobenzamido)-2,6-dimethylpyridinium chloride                                                                 m.p.                                                                             235-40° C                   1-(p-chlorobenzamido)-5-ethyl-2-methylpyridinium chloride                                                             m.p.                                                                             188-190° C                  1-(p-bromobenzamido)pyridinium chloride m.p.                                                                             244-50° C                   1-(p-iodobenzamido)pyridinium chloride  m.p.                                                                             260-3° C                    1-(m-anisamido)pyridinium chloride      m.p.                                                                             246-8° C                    1-(m-anisamido)-4-methylpyridinium chloride                                                                           m.p.                                                                             205-8° C                    1-(3,4-dimethylbenzamido)pyridinium chloride                                                                          m.p.                                                                             210° C                      1-(3,4-dimethylbenzamido)-3-methylpyridinium chloride                                                                 m.p.                                                                             240-3° C                    1-(3,4-dichlorobenzamido)-2,6-dimethylpyridinium chloride                                                             m.p.                                                                             245-55° C                   1-(3-chloro-p-toluamido)pyridinium chloride                                                                           m.p.                                                                             224-5° C                    1-(3-chloro-p-toluamido)-2-methylpyridinium chloride                                                                  m.p.                                                                             233-5° C                    1-(3-chloro-p-toluamido)-4-methylpyridinium chloride                                                                  m.p.                                                                             232-4° C                    1-(4-chloro-m-toluamido)pyridinium chloride                                                                           m.p.                                                                             223-4° C                    1-(4-chloro-m-toluamido)-2-methylpyridinium chloride                                                                  m.p.                                                                             189-191° C                  1-(4-chloro-m-toluamido)-4-methylpyridinium chloride                                                                  m.p.                                                                             194-196° C                  1-(3,6-dichloro-o-anisamido)pyridinium chloride                                                                       m.p.                                                                             205-7° C                    1-(4-nitro-m-toluamido)pyridinium chloride                                                                            m.p.                                                                             242-6° C                    1-(4-nitro-m-toluamido)-3-methylpyridinium chloride                                                                   m.p.                                                                             240-4° C                    1-(4-chloro-3-nitrobenzamido)-3-methylpyridinium chloride                                                             m.p.                                                                             220-2° C                    1-(3-(methoxycarbonyl)propionamido)pyridinium chloride                                                                m.p.                                                                             165° C                      1-(cyclohexylcarboxamido)pyridinium chloride                                                                          m.p.                                                                             185° C                      1-(1-naphthamido)pyridinium chloride    m.p.                                                                             253-5° C                    1-(2-naphthamido)pyridinium chloride    m.p.                                                                             234-6° C                    1-(2-furamido)pyridinium chloride       m.p.                                                                             214-8° C                    1-nicotinamido-3-methylpyridinium chloride, hydrochloride                                                             m.p.                                                                             205-212° C                  1-nicotinamido-4-methylpyridinium chloride, hydrochloride                                                             m.p.                                                                             250-3° C                    1-(2-phenylacetamido)pyridinium chloride                                                                              m.p.                                                                             151-5° C                    1-(2-phenylacetamido)-4-methylpyridinium chloride                                                                     m.p.                                                                             144-7° C                    1-(2-(p-chlorophenyl)acetamido)pyridinium chloride                                                                    m.p.                                                                             217-8° C                    1-(2-(p-chlorophenyl)acetamido)-4-methylpyridinium chloride                                                           m.p.                                                                             191-3° C                    1-cinnamamidopyridinium chloride        m.p.                                                                             215-7° C                    1-cinnamamido-4-methylpyridinium chloride                                                                             m.p.                                                                             235-9° C                    1-(p-chlorocinnamamido)pyridinium chloride                                                                            m.p.                                                                             258-260° C                  1-(p-chlorocinnamamido)-2-methylpyridinium chloride                                                                   m.p.                                                                             225-8° C                    1-(p-chlorocinnamamido)-4-methylpyridinium chloride                                                                   m.p.                                                                             197-9° C                    1-(2-(p-chlorophenoxy)acetamido)pyridinium chloride                                                                   m.p.                                                                             200-4° C                    1-(2-(p-chlorophenoxy)acetamido)-4-methylpyridinium chloride                                                          m.p.                                                                             181-2° C                    1-(2-(4-chloro-o-tolyloxy)acetamido)pyridinium chloride                                                               m.p.                                                                             180-2° C                    1-(propoxycarbonylamino)pyridinium chloride                                                                           m.p.                                                                             144-6° C                    1-(butoxycarbonylamino)pyridinium chloride                                                                            m.p.                                                                             129-133° C                  1-(isobutoxycarbonylamino)pyridinium chloride                                                                         m.p.                                                                             157-160° C                  1-(pentyloxycarbonylamino)pyridinium chloride                                                                         m.p.                                                                             150-2° C                    1-(octyloxycarbonylamino)pyridinium chloride                                                                          m.p.                                                                             139-141° C                  1-(phenoxycarbonylamino)pyridinium chloride                                                                           m.p.                                                                             132-8° C                    1-(o-chlorophenoxycarbonylamino)pyridinium chloride                                                                   m.p.                                                                             146-8° C                    1-(p-chlorophenoxycarbonylamino)pyridinium chloride                                                                   m.p.                                                                             155-165° C                  1-(p-tolyloxycarbonylamino)pyridinium chloride                                                                        m.p.                                                                             210° C                      1-(4-chloro-m-tolyloxycarbonylamino)pyridinium chloride                                                               m.p.                                                                             116-120° C                  1-(2,4,6-trichlorophenoxycarbonylamino)pyridinium chloride                                                            m.p.                                                                             200° C                      1-(4-benzofuranyloxycarbonylamino)pyridinium chloride                                                                 m.p.                                                                             117-127° C                  1-(3-methylureido)pyridinium chloride   m.p.                                                                             155-160° C                  1-(3-phenylureido)pyridinium chloride   m.p.                                                                             180-1° C                    1-(3-(p-chlorophenyl)ureido)pyridinium chloride                                                                       m.p.                                                                             205° C                      1-(3-(m-tolyl)ureido)pyridinium chloride                                                                              m.p.                                                                             165-7° C                    1-(3-m-methoxyphenyl)ureido)pyridinium chloride                                                                       m.p.                                                                             182-4° C                    1-(3-(m-chlorophenyl)ureido)pyridinium chloride                                                                       m.p.                                                                             125-9° C                    1-(3-(2,5-dimethoxyphenyl)ureido)pyridinium chloride                                                                  m.p.                                                                             177-9° C                    1-(3-(3-chloro-p-tolyl)ureido)pyridinium chloride                                                                     m.p.                                                                             176-8° C                    1-(3-(4-chloro-o-tolyl)ureido)pyridinium chloride                                                                     m.p.                                                                             192-4° C                    1-(3-(3,4-dichlorophenyl)ureido)pyridinium chloride                                                                   m.p.                                                                             188-190° C                  1-(3,3-dimethylureido)pyridinium chloride                                                                             m.p.                                                                             140° C                      __________________________________________________________________________

EXAMPLE 96

A solution of 1-(p-chlorobenzamido)pyridinium chloride (46 parts) inwater (500 parts) was treated with normal caustic soda solution (173parts by volume). The solid product was filtered off and recrystallisedfrom benzene to give 1-(p-chlorobenzamido)pyridinium internal salt (26parts, 65% yield), melting point 180° C.

Analysis: Found: C, 61.65; H, 3.80; N, 12.30%; C₁₂ H₉ ClN₂ O requires:C, 61.94; H, 3.90; N, 12.04%.

EXAMPLES 97-175

The following were prepared by analogous methods to that of Example 96:

    __________________________________________________________________________    1-(p-Fluorobenzamido)pyridinium internal salt                                                                         m.p.                                                                             202° C                      1-(p-Toluamido)pyridinium internal salt m.p.                                                                             162° C                      1-(2,4-Dichlorobenzamido)pyridinium internal salt                                                                     m.p.                                                                             140° C                      1-(p-Nitrobenzamido)pyridinium internal salt                                                                          m.p.                                                                             253° C                      1-(m-Nitrobenzamido)pyridinium internal salt                                                                          m.p.                                                                             155° C                      1-(3,4-dichlorobenzamido)pyridinium internal salt                                                                     m.p.                                                                             178° C                      1-(p-anisamido)pyridinium internal salt m.p.                                                                             145° C                      1-(p-chlorobenzamido)-2-methylpyridinium internal salt                                                                m.p.                                                                             123° C                      1-(o-chlorobenzamido)pyridinium internal salt                                                                         m.p.                                                                             100° C                      1-(o-iodobenzamido)pyridinium internal salt                                                                           m.p.                                                                             129° C                      1-(3,4-dichlorobenzamido)-2-methylpyridinium internal salt                                                            m.p.                                                                             169° C                      1-(p-toluamido)-2-methylpyridinium internal salt                                                                      m.p.                                                                             125° C                      1-(o-toluamido)pyridinium internal salt m.p.                                                                             112-4° C                    1-(o-toluamido)-4-methylpyridinium internal salt                                                                      m.p.                                                                             123-5° C                    1-(p-tert-butylbenzamido)-4-methylpyridinium internal salt                                                            m.p.                                                                             200-2° C                    1-(o-chlorobenzamido)-2-methylpyridinium internal salt                                                                m.p.                                                                             141° C                      1-(m-chlorobenzamido)pyridinium internal salt                                                                         m.p.                                                                             121-3° C                    1-(m-chlorobenzamido)-2-methylpyridinium internal salt                                                                m.p.                                                                              70-74° C                   1-(m-chlorobenzamido)-3-methylpyridinium internal salt                                                                m.p.                                                                             112-5° C                    1-(m-chlorobenzamido)-4-methylpyridinium internal salt                                                                m.p.                                                                             169-171° C                  1-(p-chlorobenzamido)-3-methylpyridinium internal salt                                                                m.p.                                                                             149-152° C                  1-(p-chlorobenzamido)-4-methylpyridinium internal salt                                                                m.p.                                                                             160° C                      1-(p-chlorobenzamido)-2-ethylpyridinium internal salt                                                                     liquid                            1-(p-chlorobenzamido)-3,5-dimethylpyridinium internal salt                                                            m.p.                                                                              50-52° C                   1-(p-chlorobenzamido)-2,6-dimethylpyridinium internal salt                                                            m.p.                                                                              90-94° C                   1-(p-chlorobenzamido)-5-ethyl-2-methylpyridinium internal                                                             m.p.                                                                              65-68° C                   1-(p-bromobenzamido)pyridinium internal salt                                                                          m.p.                                                                             186-8° C                    1-(m-anisamido)-4-methylpyridinium internal salt                                                                      m.p.                                                                              95-100° C                  1-(3,4-dimethylbenzamido)pyridinium internal salt                                                                     m.p.                                                                             150-4° C                    1-(3,4-dichlorobenzamido)-2-methylpyridinium internal salt                                                            m.p.                                                                             169° C                      1-(3,4-dichlorobenzamido)-2,6-dimethylpyridinium internal                                                             m.p.                                                                             120-3° C                    1-(3-chloro-p-toluamido)pyridinium internal salt                                                                      m.p.                                                                             159-160° C                  1-(3-chloro-p-toluamido)-2-methylpyridinium internal salt                                                             m.p.                                                                             128-130° C                  1-(3-chloro-p-toluamido)-4-methylpyridinium internal salt                                                             m.p.                                                                             194-6° C                    1-(4-chloro-m-toluamido)pyridinium internal salt                                                                      m.p.                                                                             149-150° C                  1-(4-chloro-m-toluamido)-2-methylpyridinium internal salt                                                             m.p.                                                                             105-6° C                    1-(4-chloro-m-toluamido)-4-methylpyridinium internal salt                                                             m.p.                                                                             158-160° C                  1-(4-nitro-m-toluamido)pyridinium internal salt                                                                       m.p.                                                                             154-6° C                    1-(4-nitro-m-toluamido)-3-methylpyridinium internal salt                                                              m.p.                                                                             163-4° C                    1-(4-chloro-3-nitrobenzamido)-3-methylpyridinium internal                                                             m.p.                                                                             156-8° C                    1-(o-acetamidobenzamido)pyridinium internal salt                                                                      m.p.                                                                             155-160° C                  1-(cyclohexylcarboxamido)pyridinium internal salt                                                                     m.p.                                                                             129-130° C                  1-(cyclohexylcarboxamido)-3,5-dimethylpyridinium internal                                                             m.p.                                                                             141-3° C                    1-(1-naphthamido)pyridinium internal salt                                                                             m.p.                                                                             150-2° C                    1-(2-naphthamido)pyridinium internal salt                                                                             m.p.                                                                             148-150° C                  1-(2-furamido)pyridinium internal salt  m.p.                                                                             224-7° C                    1-(2-thenamido)pyridinium internal salt m.p.                                                                             210-2° C                    1-picolinamido-3-methylpyridinium internal salt                                                                       m.p.                                                                             181-3° C                    1-picolinamido-3-methylpyridinium internal salt, hydrochloride                                                        m.p.                                                                             180-5° C                    1-picolinamido-4-methylpyridinium internal salt                                                                       m.p.                                                                             208-210° C                  1-(p-toluenesulphonamido)pyridinium internal salt                                                                     m.p.                                                                             214-6°  C                   1-(2,4,5-trichlorobenzenesulphonamido)pyridinium internal                                                             m.p.                                                                             264-5° C                    1-(4-chloro-3-nitrobenzenesulphonamido)pyridinium internal                                                            m.p.                                                                             195-200° C                  1-(2-phenylacetamido)pyridinium internal salt                                                                         m.p.                                                                              70-74° C                   1-(2-phenylacetamido)-4-methylpyridinium internal salt                                                                m.p.                                                                              96-97° C                   1-(2-(p-chlorophenyl)acetamido)-4-methylpyridinium internal                                                           m.p.                                                                             129-130° C                  1-cinnamamidopyridinium internal salt   m.p.                                                                             160-2° C                    1-(p-chlorocinnamamido)pyridinium internal salt                                                                       m.p.                                                                             125° C                      1-(p-chlorocinnamamido)-2-methylpyridinium internal salt                                                              m.p.                                                                             136-141° C                  1-(p-chlorocinnamamido)-4-methylpyridinium internal salt                                                              m.p.                                                                             216-7° C                    1-(2-(4-chlorophenoxy)acetamido)-4-methylpyridinium internal                                                          m.p.                                                                             135-6° C                    1-(propoxycarbonylamino)pyridinium internal salt                                                                          liquid                            1-(butoxycarbonylamino)pyridinium internal salt                                                                       m.p.                                                                              47-49° C                   1-(isobutoxycarbonylamino)pyridinium internal salt                                                                    m.p.                                                                             41-43° C                    1-(pentyloxycarbonylamino)pyridinium internal salt                                                                        liquid                            1-(octyloxycarbonylamino)pyridinium internal salt                                                                     m.p.                                                                              39-40° C                   1-(phenoxycarbonylamino)pyridinium internal salt                                                                      m.p.                                                                             116-9° C                    1-(p-chlorophenoxycarbonylamino)pyridinium internal salt                                                              m.p.                                                                             142-3° C                    1-(4-chloro-m-tolyloxycarbonylamino)pyridinium internal                                                               m.p.                                                                             150-3° C                    1-(4-benzofuranyloxycarbonylamino)pyridinium internal salt                                                            m.p.                                                                             126-7° C                    1-(3-methylureido)pyridinium internal salt                                                                            m.p.                                                                             199° C                      1-(3,3-dimethylureido)pyridinium internal salt                                                                        m.p.                                                                             155-7° C                    1-(3-phenylureido)pyridinium internal salt                                                                            m.p.                                                                             220-2° C                    1-(3-(p-chlorophenyl)ureido)pyridinium internal salt                                                                  m.p.                                                                             225-6° C                    1-(3-(m-tolyl)ureido)pyridinium internal salt                                                                         m.p.                                                                             227-8° C                    1-(3-(m-methoxyphenyl)ureido)pyridinium internal salt                                                                 m.p.                                                                             203-5° C                    1-(3-(4-chloro-o-tolyl)ureido)pyridinium internal salt                                                                m.p.                                                                             139-142° C                  1-(3-(3,4-dichlorophenyl)ureido)pyridinium internal salt                                                              m.p.                                                                             228-231° C                  1-(3-(3-chloro-p-tolyl)ureido)pyridinium internal salt                                                                m.p.                                                                             216-8° C                    __________________________________________________________________________

EXAMPLES 176-204

Aqueous solutions containing 1000, 300, 100 and 30 parts per million ofthe compounds listed below together with 500 ppm of anonylphenol/ethylene oxide condensate as wetting agent were applied to25 mm diameter leaf discs cut from French beans, Phaseolus vulgaris,infested with 50 to 100 one day old summer eggs of the greenhouse redspider mite, Tetranychus telarius. The leaf discs were then kept for 7days at 25° C on moist filter paper and the eggs examined. Theproportion hatching out, by comparison with control leaf discs treatedwith water and wetting agent alone is tabulated below.

    __________________________________________________________________________                                  1000                                                                             300                                                                              100                                                                              30                                     Compound                      ppm                                                                              ppm                                                                              ppm                                                                              ppm                                    __________________________________________________________________________    1-(p-chlorobenzamido)pyridinium chloride                                                                    0  0  0  0                                      1-(p-toluamido)pyridinium chloride                                                                          0  0  0  30                                     1-(2,4-dichlorobenzamido)pyridinium chloride                                                                0  0  0  60                                     1-(m-nitrobenzamido)pyridinium chloride                                                                     0  0                                            1-(p-chlorobenzamido)pyridinium internal salt                                                               0  0  0  0                                      1-(p-fluorobenzamido)pyridinium internal salt                                                               0  0                                            1-(p-toluamido)pyridinium internal salt                                                                     0  0                                            1-(2,4-dichlorobenzamido)pyridinium internal salt                                                           0  0                                            1-(p-toluamido)-4-methylpyridinium chloride                                                                 0  0  50 80                                     1-(p-chlorobenzamido)-2-methylpyridinium chloride                                                           0  40 70                                        1-(p-chlorobenzamido)-4-methylpyridinium chloride                                                           0  0  0  0                                      1-(p-bromobenzamido)pyridinium chloride                                                                     0  0  0  0                                      1-(p-bromobenzamido)pyridinium internal salt                                                                0  0  0  40                                     1-(p-iodobenzamido)pyridinium chloride                                                                      0  0  60                                        1-(2,4-dichlorobenzamido)pyridinium chloride                                                                0  0  70                                        1-(3,4-dichlorobenzamido)pyridinium chloride                                                                0  0  0  0                                      1-(3,4-dichlorobenzamido)-2-methylpyridinium chloride                                                       0  0  0  10                                     1-(3,4-dichlorobenzamido)pyridinium internal salt                                                           0  0  60                                        1-(3,4-dichlorobenzamido)-2-methylpyridinium internal salt                                                  0  10 70                                        1-(4-chloro-m-toluamido)pyridinium chloride                                                                 0  0  30 60                                     1-(4-chloro-m-toluamido)pyridinium internal salt                                                            0  0  0  0                                      1-cinnamamidopyridinium internal salt                                                                       0  30 70                                        1-(p-chlorocinnamamido)pyridinium chloride                                                                  0  30 60                                        1-(p-chlorocinnamamido)pyridinium internal salt                                                             0  40 80                                        1-(3,3-dimethylureido)pyridinium chloride                                                                   10 70 90                                        1-p-chlorophenoxycarbonylamino)pyridinium chloride                                                          0  10 60                                        1-(p-chlorophenoxycarbonylamino)pyridinium internal salt                                                    0  20 70                                        1-(4-chloro-m-tolyloxycarbonylamino)pyridinium chloride                                                     0  0  40 70                                     1-(4-chloro-m-tolyloxycarbonylamino)pyridinium internal                                                     0alt                                                                             0  0  60                                     __________________________________________________________________________

EXAMPLE 205

A similar experiment was performed to that described in Examples 176-204with a strain of the hop red spider mite, Tetranchus urticae, which wasresistant to the common acaricides, for example Chlorobenzilate (ethyl4,4'-dichlorobenzilate), Chloropropylate (isopropyl4,4'-dichlorobenzilate), Dicofol(1,1-bis(p-chlorophenyl)-2,2,2-trichloroethanol), Dimethoate(O,O-dimethyl S-(N-methylcarbamoylmethyl) phosphorodithioate) andPhenkapton (S-(2,5-dichlorophenylthiomethyl) O,O-diethylphosphorodithioate). None of these acaricides was active at 100 ppm, but1-(p-chlorobenzamido)-pyridinium chloride prevented egg hatching at 30ppm.

EXAMPLES 206-263

Aqueous solutions or suspensions contaning 1000, 300, 100 and 30 ppm ofthe compounds listed in the table below were sprayed on to the foliageof French bean plants, Phaseolus vulgaris. When the plants were dry,they were infested with adult female greenhouse red spider mites,Tetranychus telarius. After the mites had fed for two hours on thetreated foliage they were removed and placed on fresh untreated leaves.The sterilant effect of the comounds was assessed by noting thepercentage of eggs laid by the mites during the next 48 hours whichhatched out. The results are tabulated below.

    __________________________________________________________________________                                  1000                                                                             300                                                                              100                                                                              30                                     Compound                      ppm                                                                              ppm                                                                              ppm                                                                              ppm                                    __________________________________________________________________________    1-(p-chlorobenzamido)pyridinium chloride                                                                    0  0  0  0                                      1-benzamido-2-methylpyridinium chloride                                                                     0  0  60                                        1-(p-toluamido)pyridinium chloride                                                                          0  0  0  60                                     1-(p-toluamido)pyridinium internal salt                                                                     0  0  0  50                                     1-(p-fluorobenzamido)pyridinium chloride                                                                    0  0  0  50                                     1-(p-fluorobenzamido)pyridinium internal salt                                                               0  0  0  60                                     1-(o-chlorobenzamido)-2-methylpyridinium chloride                                                           0  0  50 80                                     1-(m-chlorobenzamido)pyridinium chloride                                                                    0  0  0  10                                     1-(m-chlorobenzamido)pyridinium internal salt                                                               0  0  0  50                                     1-(m-chlorobenzamido)-2-methylpyridinium chloride                                                           0  40 70                                        1-(m-chlorobenzamido)-2-methylpyridinium internal salt                                                      0  40 80                                        1-(p-chlorobenzamido)-2-methylpyridinium chloride                                                           0  0  0  0                                      1-(p-chlorobenzamido)-3-methylpyridinium chloride                                                           0  0  0  0                                      1-(p-chlorobenzamido)-4-methylpyridinium chloride                                                           0  0  0  0                                      1-(p-chlorobenzamido)-2-ethylpyridinium chloride                                                            0  50 90                                        1-(p-chlorobenzamido)pyridinium internal salt                                                               0  0  0  0                                      1-(p-chlorobenzamido)-2-methylpyridinium internal salt                                                      0  0  0  0                                      1-(p-chlorobenzamido)-3-methylpyridinium internal salt                                                      0  0  0  0                                      1-(p-chlorobenzamido)-4-methylpyridinium internal salt                                                      0  0  0  0                                      1-(p-chlorobenzamido)-2-ethylpyridinium internal salt                                                       0  0  60                                        1-(p-chlorobenzamido)-3,5-dimethylpyridinium internal salt                                                  0  0  0  50                                     1-(p-bromobenzamido)pyridinium chloride                                                                     0  0  0  0                                      1-(p-bromobenzamido)pyridinium internal salt                                                                0  0  0  0                                      1-(p-iodobenzamido)pyridinium chloride                                                                      0  0  0  0                                      1-(p-anisamido)pyridinium chloride                                                                          0  60                                           1-(p-anisamido)pyridinium internal salt                                                                     0  60                                           1-(2,4-dichlorobenzamido)pyridinium chloride                                                                0  10 60                                        1-(3,4-dichlorobenzamido)pyridinium chloride                                                                0  0  0  0                                      1-(3,4-dichlorobenzamido)-2-methylpyridinium chloride                                                       0  0  0  50                                     1-(3,4-dichlorobenzamido)pyridinium internal salt                                                           0  0  10 50                                     1-(3,4-dichlorobenzamido)-2-methylpyridinium internal salt                                                  0  0  50 90                                     1-(3,4-dichloro-N-methylbenzamido)pyridinium methyl sulphate                                                0  0  0  0                                      1-(m-nitrobenzamido)pyridinium chloride                                                                     0  10 60                                        1-(p-nitrobenzamido)-2-methylpyridinium chloride                                                            0  0  10 60                                     1-(p-nitrobenzamidopyridinium internal salt                                                                 0  0  0  0                                      1-(bis(p-chlorobenzoyl)amino)pyridinium chloride                                                            0  0  0  0                                      1-(cyclohexylcarboxamido)pyridinium chloride                                                                0  10 60                                        1-(cyclohexylcarboxamido)pyridinium internal salt                                                           0  50 70                                        1-picolinamido-3-methylpyridinium internal salt                                                             40                                              1-picolinamido-4-methylpyridinium internal salt                                                             50                                              1-(2-phenylacetamido)pyridinium chloride                                                                    40                                              1-cinnamamidopyridinium chloride                                                                            0  0  10 50                                     1-cinnamamidopyridinium internal salt                                                                       0  0  20 60                                     1-(2-(p-chlorophenoxy)acetamidopyridinium chloride                                                          10 60                                           1-(butoxycarbonylamino)pyridinium chloride                                                                  0  0  20 60                                     1-(butoxycarbonylamino)pyridinium internal salt                                                             0                                               1-(isobutoxycarbonylamino)pyridinium internal salt                                                          0                                               1-(pentyloxycarbonylamino)pyridinium internal salt                                                          0                                               1-(phenoxycarbonylamino)pyridinium chloride                                                                 0  0  50                                        1-(phenoxycarbonylamino)pyridinium internal salt                                                            0  0  10 60                                     1-(p-chlorophenoxycarbonylamino)pyridinium chloride                                                         0  0  0  0                                      1-(p-chlorophenoxycarbonylamino)pyridinium internal salt                                                    0  0  0  0                                      1-(p-tolyloxycarbonylamino)pyridinium chloride                                                              0  0  0                                         1-(4-chloro-m-tolyloxycarbonylamino)pyridinium chloride                                                     0  0  0                                         1-(4-chloro-m-tolyloxycarbonylamino)pyridinium internal                                                     0alt                                                                             0  0                                         1-(4-benzofuranyloxycarbonylamino)pyridinium chloride                                                       0  0  60                                        1-(4-benzofuranyloxycarbonylamino)pyridinium internal salt                                                  0  20 80                                        1-(3-(p-chlorophenyl)ureido)pyridinium chloride                                                             0  0  20 70                                     __________________________________________________________________________

EXAMPLE 264

French bean plants, Phaseolus vulgaris, were grown in 75 mm diameterpots and the soil watered with 10 ml of a 1000 ppm aqueous solution of1-(p-chlorobenzamido)pyridinium chloride. After 24 hours the plants wereinfested with adult female red spider mites, Tetranychus telarius, whichwere allowed to feed on the foliage for 24 hours and then removed tountreated plants. None of the eggs which they laid during the next 48hours hatched out, demonstrating the systemic activity of the compound.

EXAMPLE 265

Aqueous solutions containing 1000 and 300 parts per million of1-(p-chlorobenzamido)-2-methylpyridinium chloride were sprayed on toyoung french bean plants, Phaseolus vulgaris which had previously beeninfested with 50 adult greenhouse red spider mites Tetranychus telarius.The treated plants were then kept at 25° C for 48 hours, after whichtime all the mites were found to be dead.

EXAMPLE 266

1-(3,4-dichlorobenzamido)pyridinium internal salt (20 parts) anddimethyl sulphate (100 parts) were heated together at 100° C for fourhours. On cooling, crystals separated which were filtered off, washedand dried to give 1-(3,4-dichloro-N-methylbenzamido) pyridinium methylsulphate (15 parts), melting point 135° C.

EXAMPLE 267

A solution of 1-(p-chlorobenzamido)pyridinium internal salt (20 parts)in p-chlorobenzoyl chloride was allowed to stand for 2 hours at 25° C.The crystalline solid which formed was filtered off, washed and dried togive 1-(bis(p-chlorobenzoyl) amino)pyridinium chloride (20 parts),melting point 195° C.

Analysis: Found: C, 55.65; H, 3.25; N, 6.75% C₁₉ H₁₃ Cl₃ N₂ O₂ requires:C, 55.97; H, 3.21; N, 6.87%

EXAMPLE 268

A suitable wettable powder formulation was prepared by admixing:

    ______________________________________                                        1-(p-chlorobenzamido)pyridinium internal salt                                                          25% by weight                                        Wetting agent            3% by weight                                         Dyapol PFS (sodium salt of sulphonated cresol/                                formaldehyde condensate), defloculating agent                                                          3% by weight                                         China clay               69% by weight                                        ______________________________________                                    

I claim:
 1. An acaricidal composition containing as the activeingredient an acaricical amount of a compound of the formula ##STR5## inwhich R¹, R², R³, R⁴ and R⁵ are the same or different and eachrepresents hydrogen or alkyl of 1 to 4 carbon atoms;R⁶ represents agroup of formula COR¹⁰, COOR¹¹, or CONR¹³ R¹⁴ in which R¹⁰ representsstyryl; styryl substituted by halogen; furyl; pyridyl; benzofuryl orthienyl; R¹¹ represents phenyl; phenyl substituted by halogen or alkylof 1 to 4 carbon atoms; phenyl substituted by halogen and alkyl of 1 to4 carbon atoms; or benzofuryl; R¹³ represents alkyl of 1 to 8 carbonatoms; phenyl; or phenyl substituted by one or more groups selected fromhalogen; alkyl of 1 to 4 carbon atoms and alkoxy of 1 to 4 carbon atoms;and R¹⁴ represents hydrogen or alkyl of 1 to 8 carbon atoms; R⁷represents hydrogen, alkyl of 1 to 4 carbon atoms or benzoyl substitutedby halogen; and X⁻ represents one equivalent of an anion, and anacaricidally acceptable carrier therefor.
 2. A composition according toclaim 1, wherein R⁶ represents a group of the formula COR¹⁰ in which R¹⁰represents styryl; styryl substituted by halogen; furyl; pyridyl;benzofuryl; or thienyl.
 3. A composition according to claim 2, in whichR¹⁰ is styryl.
 4. A composition according to claim 2, in which R¹⁰ isstyryl substituted by halogen.
 5. A composition according to claim 2, inwhich R¹⁰ is chlorostyryl.
 6. A composition according to claim 2, inwhich R¹⁰ is furyl.
 7. A composition according to claim 2, in which R¹⁰is pyridyl.
 8. A composition according to claim 2, in which R¹⁰ isbenzofuryl.
 9. A composition according to claim 2, in which R¹⁰ isthienyl.
 10. A composition according to claim 1, in which R⁶ is COOR¹¹.11. A composition according to claim 1, in which R⁶ is CONR¹³ R¹⁴.
 12. Acomposition according to claim 1 which contains a surface active agent.13. A composition according to claim 1 which is solid and which containsa solid carrier.
 14. A composition according to claim 1 which is liquidand which contains a hydrocarbon of boiling point in the range 130°-270°C.
 15. A composition according to claim 1 which contains anotheragrochemical pesticide.
 16. A composition according to claim 15 whereinthe other pesticide is another acaricide.